在oracle中 “查询并显示每个部门的最高工资、最低工资、并按照部门编号降序排列” 怎么搞？

Question

select deptno, (select max(sal) from emp group by deptno) maxSal,(select min(sal) from emp group by deptno) minSal
from emp order by deptno desc 哪里错了？

Answer 1

错误原因是：
(select max(sal) from emp group by deptno) maxSa
(select min(sal) from emp group by deptno) minSal
group by deptno放错了位置，应该在这里去掉，在from emp 后面加上。
最好的写法是：
select deptno,max(sal) as maxSal,min(sal) as minSal from emp
group by deptno
order by deptno desc

Answer 2

(select max(sal) from emp group by deptno) maxSal,(select min(sal) from emp group by deptno),这两列里出来的最大最小值，未必是对应的deptno的，而是所有部门的最大最小值，
这么改：
select a.deptno, (select max(sal) from emp where deptno=a.deptno) maxSal,(select min(sal) from emp where deptno=a.deptno) minSal
from emp a order by a.deptno desc本回答被提问者采纳

Answer 3

你不能那么写，为什么不直接应用函数
select deptno,max(sal) maxSal,min(sal) minSal from emp order by deptno desc;

Answer 4

一句代码就叫搞定了：
select deptno, max(sal) maxSal,min(sal) minSal
from emp group by deptno order by deptno desc